Twenty-one years ago, in the shadow of the Sept. 11 attacks, George W. Bush warned of an “axis of evil,” encompassing the authoritarian and anti-American regimes of Iraq, Iran and North Korea. He did not claim that they were actually allies or partners in the style of Nazi Germany and imperial Japan. What made them an axis, in his rhetoric, was simply their ample cruelty, their shared pursuit of weapons of mass destruction and their potential willingness to share such weapons with groups like al-Qaida. The Bush address was a classic post-9/11 speech, inflating the real dangers of pariah regimes...